I do not smoke cigarettes, but I do smoke cigars regularly, maybe 4-5days out of the week. Recently after smoking them I feel light headed, and nauseaous. I ve also has less of an appetite and some mornings I have nausea but no vomiting. Also, my breasts don t usually feel sore until a week or so before my period. But it isn t due until the end of the month. Help! What could cause this? I m 19 years old, sexually active and I m not on birth control. Could I be pregnant?